Barrel engine having forced lubrication



Dec. 26, .1967 H. H. HAMLIN BARREL ENGINE HAVING FORCED LUBRICATIONFiled April 29, 1966 i 2 Sheets-Sheet 1 IN VENTOR. HALLgY H. HAMLIN a MArr'ys Dec. 26, 1967 HAMUN 3,359,864

BARREL ENGINE HAVING FORCED LUBRICATION Filed April 29, 1966 2Sheets-Sheet 2 2 -N 58 a U l 6 Fig. C

INV EN TOR. HALLEY H. HAMLIN United States Patent 3,359,864 BARRELENGINE HAVING FORCED LUBRICATION Halley H. Hamlin, Lyndhurst, Ohio,assignor, by mesne assignments, to the United States of America asrepresented by the Secretary of the Navy Filed Apr. 29, 1966, Ser. No.547,080 4 Claims. (Cl. 91-175) The present invention relates to a barrelengine and more particularly to a barrel engine having improved meansfor lubricating the various internal parts.

A barrel engine is an engine that has a plurality of pistons andcylinder assemblies having their stroke axes parallel to andsymmetrically disposed to a power output shaft. The pistons coact with awobble plate on the output shaft so as to impart rotary motion to theshaft in response to staggered linear reciprocation of pistons in theirrespective cylinders.

Barrel engines may find application in many fields, both commercial andmilitary, and one important military application for a barrel engine isthat of a propulsion unit for naval torpedoes. One heretofore knownbarrel engine specifically adaptable for use as a prime mover for navaltorpedoes is disclosed in the present inventors U.S. Patent 3,151,527,entitled, Barrel Engine, which issued October 6, 1964.

The barrel engine of the above-mentioned patent provides torque balancedcontra-rotating propellers for propelling a torpedo through water.Torque balance is required since a lack of it would impose a resistingtorque on the torpedo body and cause the torpedo to roll to one side. Apermanent inclination of the torpedo is very undesirable as it willinterfere with the steering controls. An outer housing and a hollowinner shaft are co axially mounted relative to each other and adapted toestablish relative rotation. A fluid pressure inlet, through which hotgas flows, is positioned coaxially wit-h respect to the inner shaft. Themotive power assembly includes a plurality of pistons reciprocallymounted in the housing with their stroke axes p'anallel to the axialcenter of rotation. The motive power assembly is constructed andarranged to translate the fluid pressure into an axial force component.A wobble plate conversion assembly is mounted to the inner shaft forconverting the reoiprocatory substantially linear motion of the pistonsinto rotary motion. The outer housing is rotated in an oppositedirection to the inner shaft solely by virtue of the reaction to therotation of the inner shaft.

Lubrication of the engine of the above-mentioned patent is accomplishedby a quantity of lubricant that is contained within the engine casing.By action of the wobble plate and the reciprocating motion of thepistons, the lubricant is rapidly turned and comes into contact with thepistons and other internal parts whereby heat is removed by contact. Avent tube extends radially i'nwardly from the cylindrical wall of theinner shaft to its axial center thereby providing a flow connectionbetween the casing and the interior of the hollow shaft.

As the size of torpedoes become bigger, larger size engines are requiredwhich dissipate huge quantities of heat into the engine structure.Accordingly, the lubrication, and resulting cooling, by the splashmethod is not adequate for the larger size engines. 4 I I The presentinvention provides improved mechanism and structure for lubricating andcooling a barrel engine. A quantity of lubricating oil is provided in anengine crankcase and is pumped from the crankcake to an external oilcooler. The cooled oil is delivered to a distribution ring and then to aplurality of nozzles that are provided one each in each piston. Eachnozzle directs oil against the inner surface of the piston head on which3,359,864 Patented Dec. 26, 1967 ice it is provided. The oil then leaveseach piston through a plurality of openings in the base of each nozzleand passes over the piston rollers thereby lubricating these rotatingparts. The oil is then returned to the crankcase and recirculated. Thecrankcase is maintained at a pressure equal to the pressure of theexhaust by providing an interconnecting vent line between the highestpoint in the crankcase and a hollow shaft through which gases areexhausted.

It is therefore a general object of the present invention to provideimproved lubrication for a barrel engine.

Another object of the present invention is to provide improved means forcooling the pistons of a barrel engine.

Still another object of the present invention is to provide an improvedcrank-case vent for a barrel engine for equalizing the pressure in theengine crankcase with the pressure in the engine exhaust.

Other objects and advantages of the present invention will be readilyappreciated as the same becomes better understood by reference to thefollowing detailed description when considered in connection with theaccompanying drawings wherein:

FIGURE 1 is a longitudinal partial sectional view of the aft section ofa torpedo;

FIGURE 2 is a partial sectional view of a barrel engine used to propel atorpedo; and

FIGURE 3 is a sectional view taken on line 33 of FIGURE 2 and showing anozzle.

Referring now to the drawings, and particularly to FIGURE 1, there isshown an aft-section of a torpedo housing 11 in which a barrel engine 12is st-ationarily mounted and drives a pair of contra-rotating propellers13 and 14. Hot gas, or other suitable fluid, flows from a combustionchamber into barrel engine 12 where it is distributed to a plurality ofcylinders by a rotary valve assembly. The gas drives pistons in thecylinders and the reciprocating motion of the pistons is converted intorotary motion by means of a cam that is attached to and drives a hollowshaft 15. Propeller 13 is provided on the end of hollow shaft 15 and isdriven thereby, and a second hollow shaft 16 is concentrically mountedaround hollow shaft 15 and is driven in a contra-rotating directionrelative to the direction of rotation of hollow shaft 15. Propeller 14is attached to the outer end of hollow shaft 16.

Referring now to FIGURE 2 of the drawings, hollow shaft 15 is rotatablymounted within engine housing 17 by means of radial bearing 18 andthrust bearing 19. A cam 21 and a spur gear 22 are attached to shaft 15by key 23 and are rotatable therewith. A rotary valve 24, having aninlet port 25 and an exhaust port 26, is rotatably mounted withinhousing 17 and is attached to the inner end of hollow shaft 15. Exhaustport 26 communicates with the bore of hollow shaft 15 and exhaustproducts passing through port 26 pass into hollow shaft 15 and then areexpelled into the air, or into the sea.

Six hollow cylinders 27 are positioned in a circular array about thecentral axis of housing 17, and the central axis of each cylinder issubstantially parallel to the central axis of housing 17. A cylinderliner 28 is provided in each cylinder, and each cylinder liner 28 ispositioned in the end of the cylinder 27 through which hot gases enter.Each cylinder liner 28 is provided with channels 29 through which acooling fluid may be circulated. A piston 31 is provided in eachcylinder 27 and a first roller 32 is attached to one end of piston 31 bymeans of a shaft 33. Rollers 32 engage the top surface 34 of cam 21 anda second roller 35 is attached to each piston 31 by means of shaft 36and engages the bottom surface 37 of cam 21. When hot gases enter intoeach cylinder 27 through passageway 38, these hot gases move pistons 31outwardly and rollers 32 apply a driving force against cam 21 therebycausing cam 21 to be rotated. As cam 21 is keyed to hollow shaft 15,rotation of cam 21 causes hollow shaft 15 to be rotated, which, in turncauses gear 22 to be rotated. Gear 22 meshes with gears 41 and 42 whichare driven when shaft 15 is rotated. Gear 41, which is attached to shaft43, drives gear train 44 which rotates shaft 16 in a contra-rotationdirection relative to the direction of rotation of shaft 15. Gear 42 isattached to shaft 45 which drives oil pump 46.

A quantity of lubricating oil 47 is provided in crankcase 48 and iscirculated by pump 46. Lubricating oil 47 enters pump 46 throughpassageway 49 and is then pumped through conduit 51 to oil cooler 52.The cooled oil is returned to the engine through conduit 53 and the oilis delivered to distribution annulus 54. Each cylinder wall has anorifice 55 through which the oil passes from distribution annulus 54into slot 56 formed in each piston. A nozzle 57 is provided in eachpiston 31 and passageway 59 connects slot 56 and nozzle 57. Nozzle 57directs oil against the inner surface of the piston head and cools thepiston by transferring the heat to the oil. The oil then leaves thepiston through a plurality of openings 58 that are provided in the baseof nozzle 57, as best shown in FIGURE 3 of the drawings. The oil thenpasses over rollers 32 and 35 thereby providing lubrication to theseelements, and then the oil is returned to crankcase 48 forre-circulation.

A vent pipe 61 is provided to maintain the pressure of the crankcase 48at a pressure equal to the pressure in the exhaust. As the engine isnormally operated wit-h shaft 15 in a horizonal position, vent pipe 61is located in a high position in the crankcase with its open end as farremoved as possible from the moving parts of the engine. By beinglocated in this position, there is very little oil entrainment and thegas content of the crankcase can be withdrawn at a rapid rate by asudden reduction of pressure in the exhaust, without loss of lubricatingoil 47. Vent pipe 61 connects with passageway 62 in the engine cylinderblock and orifice 63 in distribution annulus 54 and communicates with anannular space 64 that surrounds hollow shaft 15. A short tube 65 ventshollow shaft 15 to annular space 64. Cooling water is also exhaustedinto hollow shaft 15 through holes 66 in shaft 15 and serves to cool theexhaust gases. A portion of the water is vaporized and the remainingportion is thrown centrifugally against the inner wall of hollow shaft15. As tube 65 exends into the center of hollow shaft 15, little, ifany, water enters into tube 65.

In operation, hot gases enter rotary valve 24 from sta tionary nozzle 67and these hot gases are selectively distributed to cylinders 27 whenpistons 31 are in an appropriate position to make a stroke. Outwardmovement of pistons 31 causes cam 21 to be rotated, and as cam 21 iskeyed to hollow shaft 15, shaft 15 is rotated and also shaft 16 isrotated in a contra-rotation direction by gear train 44. During theexhaust stroke of each piston 31, exhaust products are expelled from therespective cylinder 27 through passageway 38, exhaust port 26, and intothe bore 68 of rotary valve 24 which communicates with the bore ofhollow shaft 15. The exhaust products, along with cooling water, is thenexpelled to the open. Gear 22, which is keyed to shaft 15, provides thedrive for oil pump 46 which pumps lubricating oil 47 from crankcase 48to oil cooler 52. The cooled oil then flows through conduit 53 todistribution annulus 54 from which the cooled oil is distributed tonozzles 57 that are provided within pistons 31, The nozzles direct thecooled oil against the inner surface of the piston heads and cools thepistons. The oil then returns to the crankcase 48 after passing overrollers 32 and 35 and lubricating these rollers.

It can thus be seen that the present invention provides improvedlubrication and cooling means for a barrel engine whereby said enginecan be driven by gases which are at an extremely high temperature.Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood, that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. A barrel engine comprising:

a stationary mounted housing,

a hollow shaft rotatably mounted within said housing,

a plurality of cylinder bores in said housing extending in circulararray about said hollow shaft with their axes being parallel thereto,

a plurality of pistons slidably disposed one each in each said cylinderbore, each said piston having a hollow hemispherical head thereon,

cam means fixedly attached to said hollow shaft and in engagement withsaid pistons whereby said hollow shaft is rotated upon slidable motionof said pistons,

a valve rotatably mounted in said housing having an inlet port and anexhaust port, said inlet port selectively providing a passageway betweena fluid source and said cylinder bores, and said exhaust portselectively providing a passageway between said cylinder bores and saidhollow shaft,

a quantity of lubricating oil in said housing,

an oil distribution annulus within said housing for distributing saidquantity of lubricating oil,

a plurality of oil nozzles communicating with said oil distributionannulus, said nozzles being attached one each to each said piston andadaptable for directing said liubricating oil against the inner surfaceof said hemispherical heads of said pistons, and

means for pumping said lubricating oil from said housing to saiddistribution annulus.

2. A barrel engine as set forth in claim 1 having means for cooling saidquantity of lubricating oil.

3. A barrel engine as set forth in claim 1 having a second hollow shaftconcentrically mounted about said first hollow shaft and having meansfor rotating said second hollow shaft in a contra-rotation directionrelative to the direction of rotation of said first hollow shaft.

4. A barrel engine as set forth in claim 1 wherein first and secondrollers are rotatably attached to each said piston, said rollersengaging said cams means.

References Cited UNITED STATES PATENTS 1,714,145 5/1929 Sperry 92l92.91,808,380 6/1931 Royal 123-4135 1,882,632 10/1932 Jaworowski.

1,896,449 2/ 1933 Kreidler 12358 2,678,536 5/1954 Morgan 91-1752,776,649 1/ 1957 Fenske.

3,105,415 10/1963 De Muth.

3,151,527 10/1964 Hamlin.

3,151,528 10/1964 Eastman 91l75 3,194,011 7/1965 Chaney.

EDGAR W. GEOGHEGAN, Primary Examiner, PAU E- MASLOUSKY, Examiner.

1. A BARREL ENGINE COMPRISING: A STATIONARY MOUNTED HOUSING, A HOLLOWSHAFT ROTATABLY MOUNTED WITHIN SAID HOUSING, A PLURALITY OF CYLINDERBORES IN SAID HOUSING EXTENDING IN CIRCULAR ARRAY ABOUT SAID HOLLOWSHAFT WITH THEIR AXES BEING PARALLEL THERETO, A PLURALITY OF PISTONSSLIDABLY DISPOSED ONE EACH IN EACH SAID CYLINDER BORE, EACH SAID PISTONHAVING A HOLLOW HEMISPHERICAL HEAD THEREON, CAM MEANS FIXEDLY ATTACHEDTO SAID HOLLOW SHAFT AND IN ENGAGEMENT WITH SAID PISTONS WHEREBY SAIDHOLLOW SHAFT IS ROTATED UPON SLIDABLE MOTION OF SAID PISTONS, A VALVEROTATABLY MOUNTED IN SAID HOUSING HAVING AN INLET PORT AND AN EXHAUSTPORT, SAID INLET PORT SELECTIVELY PROVIDING A PASSAGEWAY BETWEEN A FLUIDSOURCE AND SAID CYLINDER BORES, AND SAID EXHAUST PORT SELECTIVELYPROVIDING A PASSAGEWAY BETWEEN SAID CYLINDER BORES AND SAID HOLLOWSHAFT, A QUANTITY OF LUBRICATING OIL IN SAID HOUSING, AN OILDISTRIBUTION ANNULUS WITHIN SAID HOUSING FOR DISTRIBUTING SAID QUANTITYOF LUBRICATING OIL, A PLURALITY OF OIL NOZZLES COMMUNICATING WITH SAIDOIL DISTRIBUTION ANNULUS, SAID NOZZLES BEING ATTACHED ONE EACH TO EACHSAID PISTON AND ADAPTABLE FOR DIRECTING SAID LUBRICATING OIL AGAINST THEINNER SURFACE OF SAID HEMISPHERICAL HEADS OF SAID PISTONS, AND MEANS FORPUMPING SAID LUBRICATING OIL FROM SAID HOUSING TO SAID DISTRIBUTIONANNULUS.